Method of steering

ABSTRACT

A method of maintaining a desired distance between a steerable earth strata mining means and a laterally adjacent bore. A signal-reflecting means is placed at a known location along the bore. The mining means includes means to emit signals toward the reflecting means and another means to receive a portion of the original signal which is reflected by the reflecting means. The mining means is steered in response to the reflected signal received by the receiving means.

United States Patent [72] Inventor Arthur Lee Barrett 2928 Lothair Way, Michigan City, Ind. 46360 [21] Appl. No. 773,584 [22] Filed Nov. 5, 1968 Division of Ser. No. 570,109, July 11, 1966, Pat. No. 3,421,796 which is a continuation-in-part of application Ser. No. 202,642, June 11, 1962, now abandoned, which is a continuation-in-part of application Ser. No. 751,316, June 28, 1958, now abandoned. [45] Patented May 18, 1971 [54] METHOD OF STEERING l0 Claiins, 3 Drawing Figs. [52] US. Cl. 299/ 1, 175/26, 250/106 [51] Int. Cl E2lc 35/08 [50] Field of Search 299/1; 175/24, 41, 26; 250/83,6 (W), 106(V.C.)

[5 6] References Cited UNITED STATES PATENTS 2,231,577 2/1941 Hare 166/253 2,484,422 10/ l 949 Muskat et a1. 250/83.6W 3,019,338 1/1962 Monaghan et a1. 299/1X 3,124,690 3/1964 Savin 250/106VC Primary Examiner-Emest R. Purser Attorney-E. Wallace Breisch IIIIIIIIIIIIIIII,

METHOD OF STEERING This application is a division of my application Ser. No. 570,109 filed July 11, 1966, now US. Pat. No. 3,421,796 which is a continuatiomin-part of my application Ser. No. 202,642, filed June 11, 1962 (now abandoned) which is in turn a continuation-impart of my earlier application Ser. No. 751,316, filed June 28, 1958 (now abandoned).

Some mining methods presently in sue utilize mining mineral laterally adjacent a previously mined area and for various reasons, such as subjacent support, a mineral pillar of a sufficient lateral width must be maintained between such mined areas. The present day mining methods have difficulty in maintaining the desired distance between a mining head and a laterally adjacent mined area due to a number of factors as the mining machine is advanced deeper into the mineral seam.

By the method of the present invention the desired distance between mining means and a laterally adjacent mined area is maintained by signal generating and receiving means which relay information necessary for any required correction in the mining machine direction.

These and objects and advantages of this invention will become more readily apparent from the following description and drawings in which:

FIG. 1 is a side elevational view of a mining machine embodying the principles of this invention;

FIG. 2 is a front elevational view partly in section of an auger head support frame having a bore location sensing means thereon constructed in accordance with the principles of this invention; and

FIG 3 is a schematic representation of a location sensing means connected to a remotely located bore locating indicating means.

For purposes of this invention any suitable mining machine which is capable of mining laterally adjacent passageways in a mineral seam can be used and as shown such a machine comprises a full face auger drilling head type machine, generally indicated at 10, which includes an elongated main body portion 12; a boring head support guide frame structure 84 located forward of portion 12; and boring heads generally indicated at 114 located forwardly of portion 84 and mounted thereto at drive shafts 52 and 54 respectively.

In use machine initially bores a passageway 238 (FIG. 2) in a mineral seam, such as a seam of coal 235 bounded on the upper and lower sides thereof by layers of rock 236 and 237 respectively, and after such initial boring withdraws from passageway 238 and thereafter bores a passageway 258 laterally adjacent passageway 238 while simultaneously forming a mineral pillar 239 between such passageways. For a variety of reasons, for example subjacent support, it is desirable to maintain a minimum lateral distance between passageways 238 and 258 (Le. a minimum width of pillar 239) and to this end any suitable directional adjusting means can be used such as those illustrated in my copending application Ser. No. 570,109, filed July 11, 1966, which controls the boring direction by means fully described therein, including adjusting means carried by structure 84 which comprise power cylinders and attached lower skids, 134 and 136, respectively, and upper skids 1132. In a manner hereinafter described in detail, sensing devices of this invention relay required infomtation as to the location of the guide frame structure 84 and boring heads 14 within vein 235 thereby enabling the maintenance of I a desired boring direction.

The location of the boring head 14 within the passageway 258 is indicated by means of locating sensing devices, generally shown at 240 which include five electronic sensing units numbered 242 through 246 inclusive. Units 242 through 246 are secured to different portions of the guide frame structure 84 adjacent the outer periphery thereof, and comprise, respectively, an electronic amplifier 247 (see FIG. 3) and two spaced antennas 248 and 250, emitting and receiving antennas, respectively, for electromagnetic radiation. Antennas 248 and 250 are suitably shielded and insulated from one another in any manner well known in the art. The sensing units 242 and 244 are a diametrically opposed pair in the vertical plane containing the axis of the drive shaft unit 54 and having the antennas thereof vertically upwardly and vertically downwardly directed, respectively. The sensing units 243 and 245 are similar pair in a vertical plane containing the axis of drive shaft unit 52 being upwardly and downwardly units, respectively. The sensing unit 246 is mounted in the plane of the axes of the two drive shaft units 52 and 54 and has the antenna thereof horizontally directed towards the previously developed passageway 238 at, as shown, substantially the thinnest portion of the pillar 239.

Any suitable means can be used to detect and display bore position indicating signals generated by sensing units 242 through 246 such as the means shown in FIG. 3 with reference to unit 242 which include a power supply and signal conducting electrical conductor 157 which connects unit 242 through a line connection 160 to a suitable control panel 162, which in turn is connected to a source of power (not shown). As shown the control panel 162 includes a suitable signal resolver 252 which receives the signals of unit 242 through conductor cable 160 and passes such signals to a suitable display unit 254 such as multiple trace oscilloscope. The control panel 162 is suitably mounted on main portion 12 to enable a mining operator to visually observe signals to display unit 254 and make proper alignment adjustment to correct any undesirous deviations in boring progress through the seam 235.

In FIG. 2 there is also shown a material-depositing means or paint wheel 260 pivotably mounted in brackets 261 which are rigidly secured on a portion of the frame structure 84 opposite to the mounting of the horizontally extending sensing unit 246 and substantially in the plane of the axis of the drive shaft units 52 and 54. The paint wheel 260 is suitably supplied with a fastdrying paint, containing radioactive material for a purpose hereinafter described by paint supply means (not shown) and continuously contacts a portion of the passageway 258 farthest removed from the passageway 238 to deposit a continuous paint stripe 262 similar to a paint stripe 262 shown as having been deposited in the passageway 238 along the central part of the pillar 239 during the previous passage of the guide structure 84 and boring heads 14 in the mining operation which produced passageway 238.

In operation of the sending device 240 shown in FIGS. 2 and 3 a-substance which is a good emitter of gamma radiation or neutrons is mounted within the emitter antenna 248 of the sensing units 242 through 245 so that gamma radiation or neutrons are directed upon the portions of the mineral vein most nearly adjacent to the sensing units. Since different rates of back scattering of the gamma radiation or neutrons are assignable to coal and rock, the receiver antennas 250 will receive signals of different strength according to the thickness of the layer of coal between the emitter 248 and the layer of rock upwardly or downwardly adjacent the mineral vein 235. Such signals through the action of the resolver 252 are translated into thickness indications and exhibited in the indicator devices of the display unit 254. In the case of the sensing unit 246 the gamma radiation emitting material may be omitted from the emitter antenna 248 because the signal from the radioactive material in the paint stripe 262' received by the antenna 250 of the sensing unit 246 is inversely proportional to the thickness of the pillar 239 and is used in the appropriate indicating units of the display 254 to show the thickness of coal remaining in the pillar 239 after the boring head 58 has passed. Thus a complete set of bore location indications are available to an operator stationed at the control panel 162 to determine his actions in steering the guide structure 84 and boring heads 114 to follow undulations of the vein 235 and to correct any misalignment of the passageway 258 within the mineral vein 235.

Unit 246 can additionally be used in a manner similar to units 242 through 245 as hereinabove described by substituting reflecting or reradiating stripes of metal or the like for paint stripes 262 and 262. With such a substitution: emitter antenna 248 is provided with asubstance which is a good emitter of gamma radiation or neutrons; such radiation is directed toward such reflecting stripes, respectively; such radiation is reflected back towards receiving antenna 250 of unit 246; and receiving antenna 250 receives the radiation signal which indicates the width of the pillar 239 in a manner hereinbefore described.

it is to be appreciated that gamma ray or neutron emission which back scattering as hereinabove described in only one of several means which can be used with the sensing device 240 -to give bore location information. For instance, other types of radiation such as radio frequency waves can be applied by the emitter to the coal and rock layers with reflected energy picked up by the receiver antenna 250 giving the desired information. When using a radio frequency emitter the paint stripes 262 and 262' instead of being radioactive would consist of tuned elements such as discreet lengths of electrically conductive paint deposited upon the wall of the passageway 238 in the same position shown for the stripes 262 and 262' or if necessary could consist of metallic rods of a suitable length to be tuned to the radio frequency radiation hereinabove mentioned. Such metallic rods could take the form of nails driven into the walls of the passageways 238 and 258 by an appropriate mechanism (not shown) during successive passes of the boring heads 56 and 58 in forming of the passageways 238 and 258.

instead of the radioactive paint stripes 262 and 262 a continuous stripe of electrically conductive paint or electrical conductors (not shown) fastened to the respective walls of passageways 238 and 258 can be used. The electrical conductor in the passageway 238, being independently supplied with an alternating potential serves as a source of electromagnetic radiation to be picked up by the receiver antenna 250 of the sensing unit 246. it is to be realized that the particular type of radiation or particle emission used is in no sense a limitative feature of this invention.

Although preferred embodiments of this invention have been described and illustrated herein one skilled in the art can readily embody the principles of this invention without departing from the invention as defined by the scope of the claims set forth hereinafter.

lclaim:

l. A method of maintaining a desired distance between a steerable earth strata mining means and a laterally adjacent passageway comprising: placing signal reflecting means at a known location in a first passageway formed in an earth strata;

advancing a mining means into said earth strata adjacent and spaced from said first passageway; emitting signals having at least a component directed toward said reflecting means with at least a portion thereof being reflected by said reflecting means; sensing at least a portion of said reflected portion at a known location with respect to said mining means; and controlling the subsequent coarse of said mining means in response to such sensed portion.

2. A method as set forth in claim 1 wherein said emitting is of radioactive radiation and said sensing is of radioactive radiation.

3. A method as set forth in claim 1 wherein said placing is during formation of said first passageway.

4. A method as set forth in claim 1 wherein said sensing is of the intensity of at least a portion of said reflected portion.

5. A method as set forth in claim 1 wherein said placing of signal reflecting means is along a wall of said first passageway; said emitting is by means carried by said mining means; and said sensing is by means carried by said mining means.

6. A method of maintaining a desired distance between steerable earth strata mining means and a laterally adjacent passageway, comprising: placing a signal-emitting means at a known location in a first passageway formed in an earth strata; advancing a mining means into said earth strata adjacent and spaced from said first passageway; emitting from said signalemitting means signals having at least a portion directed towards the path of advance of said mining means; sensing at least aportion of said e mitte d signal portion at a known locatron wr h respect to said mining means; and controllmg the subsequent course of said mining means in response to such sensed portion.

7. A method as set forth in claim 6 wherein said emitting is of radioactive radiation and said sensing is of radioactive radiation.

8. A method as set forth in claim 6 wherein said placing is during formation of said first passageway.

9. A method as set forth in claim 6 wherein said sensing is of the intensity of at least a portion of said emitted portion.

10. A method as set forth in claim 6 wherein said placing of said radiation emitting means is along a wall of said passageway; and said sensing in by means carried by said mining means. 

1. A method of maintaining a desired distance between a steerable earth strata mining means and a laterally adjacent passageway comprising: placing sIgnal reflecting means at a known location in a first passageway formed in an earth strata; advancing a mining means into said earth strata adjacent and spaced from said first passageway; emitting signals having at least a component directed toward said reflecting means with at least a portion thereof being reflected by said reflecting means; sensing at least a portion of said reflected portion at a known location with respect to said mining means; and controlling the subsequent coarse of said mining means in response to such sensed portion.
 2. A method as set forth in claim 1 wherein said emitting is of radioactive radiation and said sensing is of radioactive radiation.
 3. A method as set forth in claim 1 wherein said placing is during formation of said first passageway.
 4. A method as set forth in claim 1 wherein said sensing is of the intensity of at least a portion of said reflected portion.
 5. A method as set forth in claim 1 wherein said placing of signal reflecting means is along a wall of said first passageway; said emitting is by means carried by said mining means; and said sensing is by means carried by said mining means.
 6. A method of maintaining a desired distance between steerable earth strata mining means and a laterally adjacent passageway, comprising: placing a signal-emitting means at a known location in a first passageway formed in an earth strata; advancing a mining means into said earth strata adjacent and spaced from said first passageway; emitting from said signal-emitting means signals having at least a portion directed towards the path of advance of said mining means; sensing at least a portion of said emitted signal portion at a known location with respect to said mining means; and controlling the subsequent course of said mining means in response to such sensed portion.
 7. A method as set forth in claim 6 wherein said emitting is of radioactive radiation and said sensing is of radioactive radiation.
 8. A method as set forth in claim 6 wherein said placing is during formation of said first passageway.
 9. A method as set forth in claim 6 wherein said sensing is of the intensity of at least a portion of said emitted portion.
 10. A method as set forth in claim 6 wherein said placing of said radiation emitting means is along a wall of said passageway; and said sensing in by means carried by said mining means. 